Youtube channel Amit Shukla is on your channel compared Apple's iPhone OS 9, Marshmallow Android 6.0 and Windows 10, which in truth is not out there yet in its final version. The video gives an overview of the similarities and differences in some of the basic user interface elements such as lock screen and home screen, and the system compares the notification but also some of the standard apps such as a calculator, phone, calendar and other.
Which of the three platforms is most beautiful is totally a matter of taste, while the functionality and convenience and richness of features that debate. Some will prefer the freedom and flexibility of Android, other security and guaranteed the fluidity of iOS, and third they will choose something in between in the form of Windows 10 Mobile.